Spell Rotation

There are dailies in the Firelands that ask you to kill X fire-based monsters that're cavorting amongst the Hyjal Defenders. The tip is merely this: Attack ones that are already being attacked by Hyjal Defenders. It matters not that the monsters will immediately attack you—they Hyjal Defenders will continue to fight, which helps the combat go more quickly.

Better still, if they've been whaling on the monster for a bit, you can start combat with the monster's health at half or below and still get credit.